/**
 * Adds a `version` column to saved_encounters for optimistic locking.
 * Concurrent edits previously clobbered each other silently (last
 * write wins). The route compares the caller's known version against
 * the row's current version and rejects with 409 when they diverge.
 */

exports.up = (pgm) => {
  pgm.addColumn('saved_encounters', {
    version: { type: 'integer', notNull: true, default: 1 }
  });
};

exports.down = (pgm) => {
  pgm.dropColumn('saved_encounters', 'version');
};